SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab414b1a16fd610199af6f665284cf2edcf0f0512f72b576e9f6fbc5000a1c6' 
  AND token = 'pYgCsZ1pZ79N4MZDDHnGsuOPw/9pWQZcROjLxBa0YLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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