SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8832c6ba37481d245a6107976425a800363ba01775e6ba093a1a45f7683f7796' 
  AND token = 'mtzY+Yao8eKbx1HqgnziHDCgtpx4Ip7biXhL0bj/pbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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