SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b85689c597da0d3de63c0340b88cc7396b54ed73188579f724e8a7202d08bdf' 
  AND token = 'CMJOSKHk/QcYUqNxdWURVF3Hy2xh4ZDPBR9hkS9PzRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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