SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d586083cc77d4eb6f56d3ca3ac299627657b40d9628af4ddc32fb4e61984f40' 
  AND token = 'bNiViJwEOjfiZVpMwmS9DSigFYjXzoKk3Zzwv1QFBxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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