SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '074b6317524c501a3cb2b6c83fec8e96645603f0ea1fdd16a5a79a845dca0ad3' 
  AND token = 'h3lhZViP09bIgvq9rMYeev+mXa1/eoFmbawJWBlOpeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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