SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd8ed2bc3c574d8f2e439689b80458cf861edda0e2f04afd69759461e721dc3f' 
  AND token = '9KGtSGNUJkALgh+FdFYkXvFcrSvtfkfOedUCGC6RuiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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