SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '18408fc5d63c4f06664cf978ec24c2221e06b86d024ed0dc36e5cbc1affc4680' 
  AND token = 'bjz1bB/glAGzecwk5ZbpjFZowTJwz7XNystoBs58u5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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