SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a26eb653ed13cfced521864c78a62ec76ef4441be4ce3ef90497dd52e3b5f63' 
  AND token = 'd3Pe8beO+iFhPGhShDBGDkAKubjtrnrFIjFemIRNX4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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