Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0a8fb71bbf855b86b84299e1486f3ad883cfb78974d0a4e7fa4698dbb8a476' 
  AND token = 'nO0yHS9vXS/IghwQBEKUZ2X7Kr4jlPlnsOjO4xe1ZoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}