SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26afc50fcad2dd5b5cc5d6aa42d7347a4a11a27213d5fc6cac4827728d969659' 
  AND token = 'o1+gDWEGxYXqcyMxZHwyiu2StITjXeDa3lcjSOBarM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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