SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '378fb26d84d5fcfd81b3b0c17eb33e436a318adb200508c49e3e5e822eb95f9c' 
  AND token = 'DDFv6sRbTTpTsJxQuZmUS/gBGXA6CHhgBCrNn7htiaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}