SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49dfef5e325c400bf7a963e9794cefb8b35d4cdd4bbca64c2370bbd1bfa232e2' 
  AND token = 'DCvOykS2x0B0ihyUHGVtmSw5hN5Tp/EejMiYuV0fY28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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