SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d093ff64d36b7dc4154015d22fa1ffab4c0e7dd3556107cc0789eecd3991a28' 
  AND token = 'Gq0mXV3nEbFZ+MyXY+c0/grPZOGs46athIImiNxjJRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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