SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb1882adf7442d7ac76b8bab5ab9dd2a3e5fd5f31398ef9ba0fa428006a39409' 
  AND token = 'MJTKOQG9jJxkKzCC2R7V1+hpr6FN+85ZYjc/mDmffJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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