SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fadf0092e3db9eed233f5764c18ec1664ffc5aaadc79f84e2d6031f6d66c0dd9' 
  AND token = 'Rk3ziKWh7bF0uzX6+zOxDax/56kTiITgkF5V3vJTnqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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