SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd2c620b9195209eb71da2bd586658c163d691f68864d273f0d2991528a1bba82' 
  AND token = '9LOudoKXxwqdoJATBxw/3VkqWYEtxRyXeWYPKLqLNkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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