SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e18db9d09fa2dfd797f02081ce84ef76276b3a815d1276cb7ace049eb64a44b' 
  AND token = 'ZZvgTw/22ADk/ra4fmSypEIa07ubdqSGf+6fF5aUbj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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