SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5dedd3e044698ee765bc12da0487c75a07147a894739d60074c9c9f35a81608' 
  AND token = 'dSo2h0/etqUQOKdekFe+j/ezgXRJxVTXnm6aKSAj1LE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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