SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c969e6da3ab57b7b84054edf672d165d5af323d6a66220aa843f44abb67e996a' 
  AND token = 'cPSPAyUEQJXNyALchWUwP5Z3agygtKpro2L4hR60biA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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