SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0308a6cdcfdcb980ecbf37ff07a4708d04182af369262a021335036ef8df0f11' 
  AND token = 'arDgYb03BqXiVosbvScLMmZkFK+CaP0c+MHnevHCmXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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