SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccfaf51b989940e5bff8216170ed4213ad8813c63bc17a2b28cef709fac1bdd3' 
  AND token = 'LdSof167whcK1yl6Qknn5CIwHhfgOivmlTQzG4keoQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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