SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95a62a049f605f00cd177ec660d020c855b3247e38c26569eee1a2bdaeedeb97' 
  AND token = '2Tf3mcbQyKJkmPrkovRSZ6oxKIYEnM3+jTE0aGFH8+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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