SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52707fe31e3740156d99aefebc46ebfee17c141a26a9bb3a49fe54401aa5a796' 
  AND token = 'NeeZcuRiC345/MUSvRJJbQiuvMjvRNoWbTC25lZqkO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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