SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e036548ffc0c6f6b32b4273225990281c22f5766322ec637098d9097e9f848e8' 
  AND token = '7nJpafIM4TJ68UG01vNMhlBPfHOpYB0202MMUlLyyiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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