SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec53bc5af30c5da476d0eaee7b4da9d00a163fa825c2c1250b501862b094e74b' 
  AND token = 'eyHMmiUecqUJ1eeMI0fWkbbJeCgyWC93zoAOzbQyH2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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