SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c26d75f5d09a1f364ae2836a6e5cb246e2bbd51b0851c6a97d00ca5423a052fa' 
  AND token = 'uHCQSWf6Dsk0d1tGPUAkw3afoOTUVYOalLcQZgfR/9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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