SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e4f95f8fc9e7d76240a4213fe195b4c2e6603c559708195998ebdd67a01af47' 
  AND token = 'RsxydpNgPMlPqqVSw3NxaJaeUXN8In6LRfrLQJfZxFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}