SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c0cb6d94a15c3b675edad863777f8ad09c58daa4be4f1635f28476033e34b17' 
  AND token = 'ULRJfy0O4hsjT1L1NqHOrQgZYPAK5VSolzb6wlvYdXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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