SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd15c33542bfc19a9303e9ed3914bad05075bc75669be853494749806bdd9862e' 
  AND token = '7nDl7j+SSVHWUCerF4/FB62+HlKW+2NjOpACuQQ9MbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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