SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd49105f3312c27bd2ecf498891e0c670b479bb64aaaeace23aa88ab35ea18b0f' 
  AND token = 'b0MD4jtMNturzaeacXUoUoN0Od7BnhIAM14mag7ruOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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