SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afac28b831c2b69493523b46fcaecd3e9784f8f5c9d16eb2a1b277e8538e0a4e' 
  AND token = 'P+xtlHCiajJtPflLPoXs1hrRQActye/ncCZyGWn00Q8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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