SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a0adbcd4c0d53832b5814ca59343ccbf91b1a3f66bd26e2c16096d95019ee34' 
  AND token = 'pTBxdVtdnTiR6AIe+gS4zWVjJHOBJBToFHkanVGlEww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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