SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b16b49a9cc9c5805714a0f4ac30815ae81d2b53c65a5901145501783726ddbbe' 
  AND token = 'ypD9zSiCf7iFbXAYeShYKj4X/hICKwAqg5Okv4VtckQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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