SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f90337b44b0e51793f5a4686eca31005c4156f014b765eb272f14709e1c50ba6' 
  AND token = 'kZbBopKJGzrY5oWTLVaT++EuHQ183TgFDM2JLX6d6jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}