SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7535c5b8b4b006dce1de3bd19264c12301c97787e51c1fe90d4f82ee2f22a38' 
  AND token = 'QXCxojM+wCV+NETYG6PgKkXbn1Ma7+DobewC7LxJmnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}