SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '125d2ed9980af2e078fd5b09ed49049018774b18012a25fb877438b2136014d3' 
  AND token = '8wOmFvjgIXXJsvJsGlsF54VU9JAPWlSq/7TLJUeWohU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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