SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1cde9e3f80eba9c04625d8c157380468e6b0a68928bc63dfc3f5febb249fad7' 
  AND token = '4oB8+sZwWfCI8a2v4o+g2YXzZ88n+3EAqvKFMQmivxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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