SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f19280d2ff2c8a0ab0b96ff8bae75f2a7eace0ee692c2c30da5b853b8b19985' 
  AND token = '6PwB0QUvvDjwk2Z2augsRoCY1W+vgLBQOH2EzN01UBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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