SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '887485afaf1a37dd0a25040f31ea2dd75880a6933f731282010dc8e6338b2976' 
  AND token = '+QqY9Lk6MJpnoqAFH6Md4mjDVzvgQUb23OJ/6LfLYlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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