SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5669f8f1c919551675b18c8b33821cbb83ecb43f7ce09bf108801ac1306b6d3' 
  AND token = 'ONcPeIS5vH/e1F0QC6ZUJEznHnt79ozjmrzbwNWgSNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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