SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97a1f43f59517a0d772bf9e38646f1d73c32dfa20ad0268ccdfd29042d8d9a83' 
  AND token = 'xCGft/+5s2ghvoGZgT8FRabzN4zxWgP2NPjdB8DJSnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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