SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e585b3096083469875659825b6b5d283e21fd40d746fc2ca9a0be193bd7f59c5' 
  AND token = 'RmtWI34ZZeloOFh8n0m/rs0bYA1u8O1qYfjcBDH9oLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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