SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3f34144732f95889cef0dc6c09fd61091c548b540648c7445fb3b14a20fdbd2' 
  AND token = 't7sJOKxaQZDtxBtczZwbL9wBLJW85ZLC7wDN/PgNiHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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