SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a79153fa4b00a3166fb2e64d56d5446fa80899f9da17cb7b1fb9b706147b6d' 
  AND token = 'qWpQ0su+qaFGEep00pGEeM0Ilu26HH4Bv/PIrlTq9wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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