SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '690722246c88a5c21490f93abafa1a1b06bdb1230479dbd0531c2e9bc2ea839b' 
  AND token = 'cH+8tPGLtj0FmvD46bIe3LxBAIcmu5515dS4kfhgLVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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