SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57072c29d5fb8802f14e46fe9a040d2e44c748591343b19da2a2d84461a418aa' 
  AND token = 'c3+JzpbcfZkH2E9vY8YBXea/V+htrEjc6UdbJ3lRUdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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