SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e4df4b5030ae095a423295c34ca632619fe6b214936a1555caacc8cbc90060a' 
  AND token = 'LUWXcqzKTg9TNCgnOGNbj73gOMCs0eoZafSlFgYNSDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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