SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e34101491f80914de37cccfba48dfff15c6b161137d7536e90aca531558562' 
  AND token = 'ehVF54z2s+lPPrReRrKKgzFr/sqxekoT789nnb+sbaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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