SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51e6e3290855274865e2709809a1c4b9335003c035fafa6ac27813d0d2872ec0' 
  AND token = 'dwF9DBbbtD+71G5ZE2YnyU742K64LvzfnE5leBOWWZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}