SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0ed73e9a218bffd3bb251ab3dc21c6cf22c3f768186ab103c6095e60f015b0' 
  AND token = 'Btb7QxpLfaI3SBijZZcC5H4tJgwwYsI29qPwsM3iKkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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