SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f009ed47ac582758950f7ad959d7ad05a5ff10b431e25e856d88c472aad4ba4' 
  AND token = 'RCLmIUt8QVMT6J6cG0Biw3FaEjfzEyUwIk9bs1JVS5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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