SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19367570dadb95a31c7a30c79cd051fd510ee6c02c1d1bbed2f47d6b4d47d013' 
  AND token = 'nfzs/qql0YeeA4vKo+YWPovTpetmAoRmeCHlASEXfLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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