SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66cb6be05e41f6ccf2693ce62cb380ac3425cf74f5028710b2ff0023fce577f' 
  AND token = 'lemBGXK2xugZeinXrom8do25vF9LvlwzHJj+jHr+ZWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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