SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6996970bb37d02b7e547984c3acc5b0007d1d6c5bd88338fa94fb2d3d5a31d09' 
  AND token = 'cZjdcBMR7qvr8QfebDGzmpZYGBVDCz5vmuC10XQPwhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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