SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f201736c87518bfd053f8b049f9b2dc92d9fb1e56929236c3a2fab3097b2a22' 
  AND token = 'n2Dg/ZBQlq9lz1SIZ5oIakYdV2EvN6GLBTrQq6JeLK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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