SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '247d73caf72fc6c053643c12c1e1aa5be6276345ae87413e77b0efb228813a45' 
  AND token = 'EFfx+ys1TyXTEcr4WmOa4v+oaBDsZtIX7lkcuEHaSGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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