SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2bc2336d1e91a79941a3b6485522f2a4f0adf6180c5be4a0595727b79f7b3443' 
  AND token = '+0WqeDZdIkMI+ktkxp5ZmfEtGj0lKoC98nAHJ9pnupw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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