SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65f8dc1569d4bdf020f6e01be02b8b0b028baaa5eb02350e8112e182ec6b19c2' 
  AND token = '3tGNWG8Bj7N6RFETuWgwFssutfENVS5Y8I8k7+GjdDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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