SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce4d1143bf7ffdf902a125fb9938d8b8bac2aa5325ed387a9ee0be4eb717a099' 
  AND token = 'tm63U+NTgytjiEUHFG/2ok80+C7kiHL70xq+PXMSpAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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