SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79af913a74560df4cb23731af0e345e198f211843e67a21071c5c2a1baaf85b' 
  AND token = 'HsTa0bU8KJXZ9twA+RWEJUPZaJ/xgduXR10MHXv2q2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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