SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7ecf550ecb95f16494e8b77da76302e51820811abdadba51a7621974269c9ab' 
  AND token = 'vjZ+S7Vmc4o6G0ht3DXhlIr1Pw3EXFeiHx/J9J6WTzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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