SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfae7fd5479d0346d1f35cc3a123b33c86ed65d0a70eecc677c495da5f1b4216' 
  AND token = 'iogjMKGZYulPkvoeip9favvxkQtNHy9PlovXduLO1rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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