SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68777b111e014df121bd8fcd51e554a8085b0a55df944943f534ff51d3701365' 
  AND token = 'HzL2AYqgIL2cHQcnqOFPSKoQ5Ix23yaLoON8rk1cPZY=' 
  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"
    }
  }
}