SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccdf2a63347ac9745f6b22a7435bac1a007dbcadcc2a9940fd9718105bbeba2a' 
  AND token = 'RWXb4E9Q31lEbzPIg8c1GVOaSnwb3kK79LZ6jZ5Hp4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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