SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f915ea458ed795084d6f782d019bd9e830e9bc89f69072792d596073a2ad109c' 
  AND token = 'jmIO+JE1lGANgi8FQOhqYkJnGpeRkx3wHQ3V0GpPHrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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