SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd429d4543898d41440d27accc7716d34078cb3673dac75d063a82f17af15dbe8' 
  AND token = '2HvO1Y2fJWaL/Ua5ORzkKK5LuUDo6XtvgDSmQ6GFKOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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