SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9030c0ab937706c38051d4d27744bf2bbafd442593f8ff3e5c47292832b335fb' 
  AND token = 'txixcqdpZylVagctTmMBPutVVx4mW0TVbbgkHzVFHj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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