SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ebefa1846004d9f5bd912e6bcea71873b2489ac5dc6c36c5dfc1d64d21eb6e' 
  AND token = 'GrnBE5D8Y2+TsHHuqnXvMk/bzY352VSgwTHMPAyg3SY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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