SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1630c43b1daf24593abdca5f235da8399aea4d147bffd54abf877a23c9fb6866' 
  AND token = 'VcEBFXRofbp/oZ5hktbhedieSVYfbQutNcmnbkcsk1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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