SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '76a037e89dc3ef884bf35c669a64f65d54acad2d43998fb9e1262cbb21d7bae5' 
  AND token = '2MD3mtfX2lLjYswllnodrgiXt+LLVCEkLwAGLKUwFts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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