SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bdb2b94f77947a5907841ddf76f80d55140d7c2fbeea1764e0e9f914cd1d999' 
  AND token = 'I0lgkTVtcATHGs9UifLz4wDrj/D5uKQ3JOZKeXr4Cag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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