SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eff2e6de66ef7280e683fcc83e0ddda87e1cb2893f067838cbfd99858940a993' 
  AND token = 'ftvayhGa74AMGqRUDM5qztVPTjv8Qx0vf2CDs+WTP4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}