SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bcf7a2a1c4134fb899715ea2a3eacae487c684d19d8b80ed485769cbb13468c' 
  AND token = 'jDQJJzYKF21DvQyVigx5dJQqaZ2sQveMelNhH1GygyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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