SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625cd64ee7ab64b78604745dae30e12da97a2a67035342319bf51d574bb8cafc' 
  AND token = 'FpudmX8DhOdYVXr5FWFw7ixVwZtnAu8jZrVtCYqHqh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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