SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b0b9fd3807700fb6181bee196302deee14461b8b7225fe8b3f2267b554c9f19c' 
  AND token = 'I+vq93CLOYMqAAOfFkluMNQ0Bk8/N2YNeImxefT4/+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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