SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a0f1025cf23cc6cbb4d0f793a2775a49d211dd55cace84ca492045264824d0' 
  AND token = 'bHZtdPjDhQRi+yh1rgGq4SbG/ntg8JwGcwpKtG5DCTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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