SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '227e2eeec27b86d712da410056409ca0b3066714978ed5f2832618581d4868d0' 
  AND token = 'aBbvwtSgNG6XZljKwv9ndSyhR6hMn6izX435UxTNcO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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