SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '981b1c317fcd48c2c6fe0a9ae625d43ebb75a8d78c0da488ee1ee23c50ffee1a' 
  AND token = 'TA7PTvwHIO5OFuAUS0IsVqmYF7FER8E+fEEY9eUG80w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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