SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0850c180895abecf3753348e1fccaa06bb0a9cae70cede496500ef5881fe8e9a' 
  AND token = 'qiwr5FeZJCeDVMgWTXt7RlsR2H8aHp85wmIQWPZwvyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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