SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c02cdb7cbf377199da9256742758150f7bf3ad59186d0fcbee60ecc2f5fa622' 
  AND token = 'Tgz1oDLi3RHsLj06/bhiw3L3zINWj+DKjJP5EccQWwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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