SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '199bf897376fd6f1f0c68c16008fa6832118056e557ea398ba7abe4bbb8f1839' 
  AND token = 'B/UOfNyLSw+ltXs/uXsh6RLjBlo77qcvV1hA4bwZFm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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