SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19e37c21548bef554704aa5a58f2b30194030d4314ff2ac9f703d6f9b0437602' 
  AND token = 'n+p4Y9g75io96/tF0HdTzO8rnnV/yXs3hU4VtAAVK3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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