SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a56ad6a4ee283bc7a480379dd35fa05aa39183f40887ead98dfd9860e58f97c' 
  AND token = 'Z2np9Cb4MxODXmLxkwtdRAn16zizp2FFcHWjWVV6tgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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