SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f137326510e08ddc421359cd2ed5b29ccafc4041adcdec930708f2d114a558b4' 
  AND token = 'roXM6ywFeMPFIXq2ZDQ/jopozAROeNEU6EbiR8s579E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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