SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f9b7d18ad9cecaf494facf31fdc6bbc46a30449dfef43471fa0b96367237537' 
  AND token = 'l6EIYk9reKZXucfAmAOcUexuOtZ+bVmJ+XJOGbySn5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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