SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2915a6557e6ce1ff2ca62dfab60c0c0635399b41be591b47387b6673b4b4bff7' 
  AND token = 'aGlwNYUnDYj4KZOzad2mHP4CFR0QFPJmc1VBI8YYqgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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