SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee7a62804056810f28b01ccfc7bdecfdaa274f0e4f7b868e2a6b0736e05f452' 
  AND token = '7Uv+r7Uo8bqKP/EaJlO1OjfOtBqbwkNAl9MPSKxbPog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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