SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf963bc9ac8de97dd4096c550815bee868f505b0c84b587b07ad4708704f6ff0' 
  AND token = 'ffN5qoreeXfuAxaCaZ1p51F3FuAb80Crafs8Dfzq0SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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