SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef39b706229b51f776caa3b12322ebbf10d6bc8b74cf6d218bcd971d201b4ae6' 
  AND token = 'B+yJ9Hu0pgyNSszvMSPCp5GO4yGxvCuYoqK8jnvvGuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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