SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46fe3deb47ecbad134dbb6548f3a6246738420359cbd91c513294e74f94a6d83' 
  AND token = 'YP+qZwK8ZzTDVUzXVQR3O8dpcRK/HA7w+r6V3ii4rPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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