SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a73176d9bc443ec06f47c03c9d2f640f97ff3bdba90b37a6bb52a01d1361f63' 
  AND token = 'b0OZoocRqg9mmx4EFgdz4BTHIwPXFTCZWbNrQQoqoyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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