SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a734e58acd1d75970548d87a5606aaa6cff1f3e0ca61c70f0cd23549011045e' 
  AND token = '5yvqV/IB6Ast2uj++/ORuKirXKnFBZ4jGphlGVK2pwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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