SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4bd1871682dfd6d3d596d0ab102a775b4cc894e1fce72b0b17bc1ff784b12ef' 
  AND token = 'A5aueRKkMyg4v9osP1DP+/FuIQCd2in2Xplcd8fqSCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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