SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80afcd3d8a32265498b48397c3a0fced40bf0d2a0fb8b28666605cc8ec8a5c1a' 
  AND token = 'rSKk+436bEsIIpkQdz22q6F/1z0MapmqTiNH7oLlEIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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