SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea388c8e82db44ab3c74f116f96527205a3103878c28e9ac832287881f785a8c' 
  AND token = 'y09BydlpyrfCNbi+CiG8Fu/EKJUQHKI9tjhGTtXvLjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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