SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ebe3f78ebcd2f8f3198bcb6cdcd9195693ce51096249502fc543e7fa843b61' 
  AND token = 'GyIWsdYQZcOAcbuwB1NYSF0IWauYRZEhgZKCcXq89ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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