SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5333c794bf57a1a8d8283aa76d07f5fa5740d1cf6522796099db7a120e93cb3c' 
  AND token = 'xYvZG2W/8tB0pQstqj8T7HEFo9qtcAtaOMus0CZ8ezg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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