SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3779960beadc9360440d741d6a50c147da9e62ba5b3460705507ee3adef4df' 
  AND token = 'mwpG64bFgOM/TH3Byh7Q8ykwQZwFsaP2QQD5DWDnlpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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