SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '825b8af2382b89fe56295caf93e66057eaa3f74cd16cfbf12adef61133b8499b' 
  AND token = 'KyvXftTmdd/jEH/O1Q6Gn+EDiASXEbY0AwpLZC4VDCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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